Towerhill, Colorado

A resort town in the mountains of Colorado where much of the story takes place. While Towerhill is relatively free of pollution compared to places like California, it is still affected by the decline in the environment and the rise of technology. A sonic boom from a supersonic aircraft causes a massive avalanche in Towerhill, killing many people. The commune where Decimus Jones is leader is located near Towerhill

Denver, Colorado

The largest city in Colorado and the home of many of the story's characters. Denver becomes the scene of widespread panic and violence when the water supply is poisoned by escaping nerve gas disposed of in underground caves.

California

One of the most polluted of the American states in the story, where people routinely wear filter masks while outside and the smog and cloud cover is so thick the sun is rarely seen.